Process and apparatus for reducing pulp or the like



L. T. MURPHY 1,726,756

PROCESS AND APPARATUS FOR REDUCING PULP OR THE LIKE Sept. 3, 1929.

Filed Jan. 19, 1927' 2 Sheets-Sheet l DEQQAI IN V EN TOR.

Sept. 3, 1929. MURPHY 1,726,756

PROCESS AND APPARATUS FOR REDUCING PULP OR THE LIKE Filed Jan. 19, 1927 2 Sheets-Sheet 2 ATTORNEY Patented Sept. 3, 1929.

LLOYD I. MURPHY, OF IIRANKIILIN, OHIO.

PROCESS AND APPARATUS FOR REDUCING PULP OR THE m Application filed January 19, 1927. Serial 1T0. 162,085.

This invention relates to improvements in process and apparatus for reducing pulp, in which the processes of reduction are continuous, without interruption for charging,

dumping and cleaning portions of the apparatus, as the stock breaker or beater, which in the common type of apparatus become clogged with foreign materials contained in the raw stock. The main object attained in the invention consists in means associated with a stock beater or breaker for elfecting separation from the mass of stock, in process of reduction in the apparatus, of heavy foreign substances, as fragments of metal, rock, glass, etc., which are found in various degrees in old paper and rag stocks, and which separate from the pulp mass and settle in the beater tub unless otherwise removed.

The common practice is to interrupt production at frequent intervals and remove the accumulation of such foreign substances by shoveling the same manually from the beater tub, then recharging the beater and continuing reduction until the apparatus again becomes clogged and reduction of the pulp stock is interfered with by the irreducible foreign matter accumulated in the bottom of the tub, when production is again interrupted while the beater tub is emptied and cleaned, production and interruption for removing the junk thus following one another with reatly retarded output.

A. urther important advantage attained by the improvements of my invention consists in uniformity of grade or production, both over reduction and under reduction of the pulp stock, being avoided by themeans provided for separating the finished stock, 0 i. e., the part that has been reduced to the required state of fineness, continuously from the mass of stock in process of reduction, and

thus preventing over disintegration of fibrous materials which make the finer grades of pulp. Under reduction of the coarser materials cannot result because all the stock 1 is continuously in process of reduction by hydration and the action of the beater thereon until the required state of fineness is arrived at. a

A further object attained in my invention consists in the elimination of certain units of the apparatus required in ordinary reduction systems, as the settling trough and wet machine or stock thickener, and the intermediate pumps and connections for moving the stock from one unit to another. The economies elfected in the first cost of the improved apparatus, in maintenance, space savmg and operating ower amount to a very material item in re uced cost of production.

'lhe invention is herein illustrated and described in two general forms with respect to the features of the apparatus for effecting continuous separation of the fine pulp from the coarse, the illustrations and description in one form being similar to the inventions subject matter set forth in my copending application for Letters Patent Ser. No. 16,268, filed March 18, 1925.

In the accompanying drawings which serve for illustrating the invention:

Fig. 1 is a view in side elevation, partly in section, of the junk removing apparatus in general form irrespective of modifications of the stock beater, the stock beater being outlined in end elevation;

Fig. 2 is a view in end elevation of the junk removing apparatus, the stock beater being indicated in side elevation;

Fig. 3 is a detail'view, in a preferred form,

of the fine pulp extractor;

Fig. 4 isa detail view, of the fine pulp extractor in a modified form.

4 As shown in Figs. 1 and 2 the complete apparatus consists of the stock beater 1 which may be of any suitable construction, the same being illustrated conventionally to represent the special features illustrated in Fig. 3, and thejunk removing apparatus which is located at the side of the beater, as here shown, and comprises a pit 2 formed of an assembled metal casing, the several parts being joined together as indicated at3 to present a shoulder 4 forseating a gate 5 for closing the passage from the heater to the pit when the apparatus is stopped, and an overhead structure consisting of a frame 6 upon which is supported a wheeler drum 7 traversed by an endless carrier 8 provided with a series of buckets v9, the course of the carrier being over a guide wheel 12 and through the pit 2, the carrier being directed over a guide '10 inthe pit to I cause the bucketsto scrapethe bottom of the pit and scoop out'the foreign substance which settles therein, the bottom of the pit being recessed as indicated at 11 for effecting the scooping action of the buckets. The carrier duction, and to facilitate re wheel 7*may be actuated by an suitable power means, as the motor 13 here s own as having a direct drive connection with the wheel 7.

As the carrier buckets pass over the wheel 7 the junk carried up by the buckets is dumped into a lar e vat 14 provided with a door 15 for removing the junk. A water line pipe 16 is connected to the vat for flushing the same at intervals to remove the adhering pulp from the junk, the pulp being salvaged, as the water rises in the vat, in an overflow box 17 to the beater through a chute 18.

A pipe 19 connects the overflow box with the beater hood 20 which serves for effecting circulation of the water between the vat 14 and the beater upon flushing the overflow box which is done several times each day to prevent the overflow box becoming clo ged. A branch pipe 21 leading to the sewer fi'om pipe 19 serves for conducting the refuse into the sewer when the overflow box is emptied for inspection, etc. The overflow box is also connected with the pit 2 by means of a pipe 22 which is constantly open, except when pipes 16, 19 and 21 are to be opened, and serves to return the water discharged into vat 14 to the pit, a branch 31 of pipe 22 serves for directing a stream of water over the buckets 9 for washing ofl free portions of pulp carried up with the junk from the pit, the same being thus returned direct to the pit.

The main object attained by the junk removing apparatus in combination with the stock heater is continuous reduction of pulp without interrupting the reduction processes for removing the unk from the beater tub as in the usual practice.

To this end any suitable means may be employed in the practice of the invention for separating the fine pulp from the pulp mass in the beater continuously, thus to avoid over reduction of the materials which yield most readily to the processes of hydration and reuction generally and improve the quality and increase the volume of the output.

In ordinary practice where old paper and rag stocks constitute the bulk of the raw material, the reduction apparatus becomes clog ed with the junk and must be shut down Ereuently, every week or ten days according to t e condition of the raw stock, for cleaning the junk out of the beater tub. Thus reduction is slowed down by the accumulation of junk in the beater and is stopped entirely by the shut down for removin it. Furthermore, the accumulated mass 0 junk and slime in the beater becomes so enmeshed that it is difiicult to remove.

These conditions are greatly relieved, being practically overcome where average grades of raw stock are used, by the improved apparatus herein described. Also certain units of reduction apparatus ordinarily used, as settling troughs and thickeners and the intermediate pumps for conveying the stock are notrequired. The preferred forms of beater equipment for removing the fine stock from the pulp mass continuously, as reduction in the beater proceeds, consists, as illustrated in Fig. 3, of a pulp extractor comprising the hood 2O disposed over the beater roll, and having a series of apertures 26 through which the portions of fine pulp pass, as the pulp mass is thrown, by the centrifugal action of the beater roll against the hood, the apertures being of the required size to effect the desired grading-of the finished pulp by preventing passin of the coarser portions of stock. A series 0 scrapers 27 are reciprocated back and forth over the apertured portion of the hood to prevent clogging of the extractor, the extracted pulp being conducted from the beater by a chute 28 for further disposition as may be required.

The pulp extractor, substantially as shown in Fig. 3, constitutes the inventions subject matter of Letters Patent of the United States, No. 1,244,144, October 23, 1917, and, therefore, does not require detail description herein for an understanding of its application and use in connection with the invention herein set forth.

The means for separating fine material from the pulp mass in the beatertub illustrated in Fig. 4 consist of a perforated backfall 29 associated with the beater roll, the pulp being withdrawn from the beater through a suction box or chest 30, the arrangement as here shown being substantially the same as the inventions subject matter of United States Letters Patent No. 1,271,426, July 2, 1918.

The two forms of extractors herein shown l and described in combination with the junk remover attachment serve to illustrate the principle and function of the invention, which consists in means associated with a stock heater or breaker acting to separate the fine material and the foreign material, or junk, from the pulp mass in the reduction apparatus continuously incident to the processes of reduction.

It is obvious that modifications can be made of the apparatus as herein shown and described without departing from the rinciple and spirit of the invention as de ed and corInIprehended in the appended claims.

' aving described my invention, I claim:

1. An apparatus for reducing pulp including in combination with a stock eater, a receptacle at a lower elevation than the beater tub for receiving foreign materials sepafor removing foreign materials from the beater, a vat for receiving said materials, an overflow box in said vat connected for returning salvaged stock to the beater, and means for flushing the vat to cause salvaged stock to enter the overflow box.

3. An apparatus for reducing pulp including in combination with a stock beater, means for removing foreign materials from the beater, a vat for receiving said materials, an overflow box in said vat connected for returning salvaged stock to the beater, means for flushing the vat to cause salvaged stock to enter the overflow box and a connection for returning water from the overflow box to the beater.

4. An a paratus for reducing pulp'including in com ination with a stock beater, means for removing foreign meterials from the beater, a vat for receiving said materials, an overflow ox in said vat connected for returning salvaged stock to the beater, means for flushing the vat to cause salvaged stock to enter the overflow box, a connection for rean overflow box for returning salvaged stock to the beater and a connection for returning water from the overflow box to the pit.

6. An apparatus for reducing pulp including in combination with a stock beater, a pit connected with the beater for receiving foreign materials separated from the pulp mass by gravity, means for shutting 'ofl the pit from the beater, a vat for receiving said materials, an overflow box in said vat connected for returning salvaged stock to the beater and means for flushing the vat to cause salvaged stock to enter the overflow box.

An apparatus for reducing pulp including in combination with a stock beater, a receptacle at a lower elevation than the beater tu for receiving foreign materials separated from the pulp mass by gravity, means for removing said materials, and means acting on pulp material centrifugally for separating fine material from coarse.

8. The herein described process for reducing pulp stock consisting in hydrating and beating the stock in causing foreign materials separated by gravity from the pulp mass to move to a lower level and to be removed, and in causing centrifugal action on the stock to separate fine from coarse pulp incident to processes of reduction.

In testimony whereof, I aflix my signature.

LLOYD T. MURPHY. 

